The Lost Experience was an alternate reality game that was part of the American television drama Lost. The game was developed by ABC in the United States, Channel 4 in the UK, and Channel 7 in Australia. It was written by Jordan Rosenberg and created by the agency Hi Res. The experience played out during Lost 's second season in the United Kingdom and during the summer break in the United States until the launch of season 3. The Lost Experience, which was announced by the United Kingdom's Channel 4, Australia's Seven Network and the United States' ABC on April 24, 2006 and began in May 2006, used websites, voice mail, television and newspaper ads and a novel to give players clues to the game. The Lost Experience ended on September 24 2006. Damon Lindelof has verified the canonical status of The Lost Experience and the information provided therein.

ABC Entertainment's senior vice president of marketing, Mike Benson, described the game as a hybrid between content and marketing. This type of marketing was previously used by ABC for Lost's premiere in 2004. ABC created a website for the fictional Oceanic Airlines, the airline of the plane that crashed in the show's pilot episode.